Pump plunger



T. GORDON.

PUMP PLUNGER. FILED NOV. 29.1921- Maf. 1s, 1923.

III...

Patented Mar. 13, i923.

.NET

1,448.624 orioo PUMP PLUNGER.

Application filed November 29, 1921.

To all whom t may concern.'

Be it known that I, THOMAS GORDON, a subject of the King of Great Britain7 residing at Excelsior House, Murray Street, Perth, Western Australia, Commonwealth of Australia, have invented certain new and useful Improvements in Pump Plungers, of which the following is a specification'.

My invention relates to that type of pump plungers in wlhich cup leathers are employed and the object thereof 1s toproduce a more eiicient plunger for which 'the air is fed to the compression side of the plunger in an abundant manner and preparatory to the compression stroke being made.

The chief structural feature of the invention resides informing the metal plunger head with peripheral marginal inlets or passages which yallow the feed air to lio-w freely to the compression side of thev plunger during the idle or return stroke-said feed air flows through said passages and cireumferentially between the cup leather and the Wall of the cylinder or barrel.

A further structural feature in combination resides in the metal plunger head having on its compression side or face aperipheral on marginal recess or rabbet formation thus thereat providing a gap or cavity to allow the cup leather to freely and outwardly expand or bulge and prevent the escape or return of any air to the feed-side of the plunger during its compression stroke. The

resultant air pressure on the said comp-ression side automatically causes said cup leather to expand and to be maintained in such expanded position during the said compression stroke. My invention prevents (as hitherto the practice) the plunger during its compression stroke from moving a certain distance in its'cylinder practically idle and before it becomes fully effective as a pumping. agent and by my invention loss of time and high pressure lair is avoided. In order thatthe invention may be clearly understood reference will be made to the attached drawingsA wherein- Fig. -1- is a view partly in elevation 4 and partly in section showing a pump'plun- 'ger made in accord with this invention and in said View the cup leather is shown in its normal or unexpanded position and the flow of the feed air is denoted by tliefull arrows. Fig. 2 isa plan view.

Referring -to said drawings the metal plunger head as a is held on the reduced end Serial No. 518,709.

portion b of the rod c and secured by the loose metal Washer Z and nut e. In the peripheral margin of said plunger head lare formed a number of inlets or openings f which (when the plunger is at its return or idle stroke) act as inlets and passages for the air from the feed side w of the plunger for the therethrough passage of feed air to the opposite or compression side y of said plunger. The plunger head a is made with a peripheral or marginal recess or rabbet m which thereby and thereat provides a cavity or gap to permit of the flexible expansion of i seen in Fig. -1- is held in position between the loose metal washer d and the reduced or rabbeted portion m of the plunger headsaid washer in practice is smaller in diameter than the rabbet m. In the working of the invention assume that the plunger head a. and cup leather is at the idle or return stroke and moving in the direction of the broken arrow shown in Fig. -1- the feed air as denoted by the full arrows consequently rushes freely from the feed side m of the plunger and thro-ugh the peripheral openings j' of the plunger head afand circumferentially between the cup leather j Vand the` wall n of the cylinder-said air then passes into the compression side y for the subsequent compressi-on stroke and immediately upon the start of such stroke the cup leather j by reason of the resultant air pressure will automatically and outwardly expand and make close contact against the wall n of the cylinder and which expansion is facilitated and 'made more positive by the relief cavity formed by the rabbet m of the plunger head a and said cup leather by said expansion provide a tight close seal againstI the escape or return of air from said compression side y during the compression stroke of thev plunger. The` rush of air through the openings f'hlas the further tendency to reduce the normal size of the cup leather j and thus form an eective free air way during the return or idle stroke of the plunger aforesaid.

It will therefore be clearly seen that this invention produces an instant compression dered highly effective for .the fullllength of such stroke as a pumping agent.

The present application is a continuation in part of my prior application, Serial No. 377,846, filed April 30, 1920.

`What I claim as my invention and desire to secure by Letters Patent is l. In combination with a pump cylinder, a pump plunger head equal in diameter to the bore of the cylinder, a cup leather secured to the compression side of the pump head, said head being formed with marginal openings on its periphery and with a. peripheral marginal rabbet or recess to thereby and thereat provide a relief cavity for the outward expansion of the cup leather and to cause same to make close contact against the wall of the plunger cylinder during the compression stroke of said plunger as herein described and shown in the attached drawings.

2. ln combination with a pump cylinder,l

a pump plunger head equal in diameter to the bore of the cylinder, a cup leather on the compression side of the head, said head being formed with marginal openings to provide air inlet passages for the free feeding of air to the compression side of the plunger during its idle or return strokesaid plunger being also formed with a marginal rabbet to provide a relief cavity for the outward expansion of the cup leather during the compressions stroke of the plunger said plunger head and cup leather in operative combination with each other and with a pump barrel or cylinder as herein set forth and described and shown in the attached drawings.

3. A pump plunger comprising af head having marginal openings and having a circumferential depression on its compression side, a cup leather on the compression side of the head and a Washer of smaller dialneter than said head, positioned against said cup leather, and a nut for securing said cup leather and washer in place.

4:. ln combination with a pump cylinder, a plunger comprising a head equal in diameter to the bore of the cylinder, said head having a circumferential depression on the compression side of the head and peripheral passageways communicating therewith, a cup leather secured to the compression side of the head and extending over said depression.

5. A pump comprising a barrel, a plunger rod reciprocable Within said barrel, a piston head secured to said plunger rod having a back portion of slightly smaller diameter than said barrel to form an air leak therebetween, and a front face of smaller diameter than said back portion, forming with said barrel a circumferential recess, a washer of smaller diameter than the front face of said piston, a cup leather clampably held between said washer and front face, having a flexible portion bending away from said piston head at, the edge of said washer on the suction stroke, and beinfg successively pressed into Contact with said ront face and into said recess, with increase of pressure upon the compression stroke.

ln testimony whereof l have hereunto set my hand in presence of two subscribing witnesses.

THOMAS GRDON.

Witnesses:

RICHARD Srannow, FRED H. LAMBERT. 

